Septic tank at summer cottage winter layup

[220 Swift]

What does everyone here that has one do with theirs. I have had it sucked out in the past and have left it partially full. The year i left partially full i had a trailer over top and no snow cover for insulation.

The previous owner had it emptied when i bought it.
I have heard its good to have it partially full as it keeps the ground from shifting or heaving.

A guy at work said he left his full one year and no issues. May have got lucky ?


1500 gallon capacity.
0.7meters of top dirt cover
1.5 meters of storage.

Every winter can be different with snow cover so this is a concideration.

[fish_e_o]

it's below the frost line it wont freeze

some fresh poop breaking down will heat things up if you're worried

[Deasoninc]

If you are worried about it freezing , just put in some RV Antifreeze right into the holding tank . That will keep your poop from freezing . That's what we do at our lake lot.

[220 Swift]

Thanks guys. I may dump some down and makes sense on the breakdown heat.

[chuck0039]

I have always been told If your tank is fiberglass, you should leave a few hundred gallons in it to protect it from frost heaving. If it is concrete, not sure if it matters.

[Big Grey Wolf]

Couple years back most cabin septic tanks froze on lake lots on our street as limited snow before Christmas. If not tub of warm water going in and bacteria chewing away is risk. Depth below surface very important. Best thing could have done is Styrofoam on top before backfill if shallow tank. Hope for lots of fluffy snow, could shovel some on top if minimum amount but do not pack, no driving over tank area.